The immune response triggered by SARS-CoV-2 infection may mistakenly target cells crucial to the blood-brain barrier and increase the risk of bleeds and clots, a small study suggests.

The findings, based on autopsies of nine individuals who died suddenly from COVID-19, suggest both short- and long-term neurological complications from the disease, according to US researchers.

The National Institutes of Health-led team say the data are consistent with results from an earlier study that showed the virus did not infect the brain directly.

In the current autopsy study of the brain, neurologist Dr Avindra Nath and colleagues examined the vascular pathology, neuroinflammatory changes and immune responses of patients who died during the first wave of the pandemic.